In certain parallel processing systems containing a plurality of data processing nodes, one or more switching units are provided for transferring data between the data processing nodes. A switch unit receives a connection request from one of a plurality of nodes and establishes a link between the data processing node which sends the connection request, and another of the plurality of data processing nodes, which is requested by the connection request. As used herein, a “switch node” means any node of the plurality of data processing nodes which is capable of connecting to such a switch unit. A switch node includes a device driver and at least one adapter.
Conventionally, during diagnostics testing of a switch node, a diagnostics program loads special microcode to test the adapter hardware. This process typically requires a device driver of the node to stop all send and receive requests and input/output controls issued other than for the diagnostics program. Open windows on the switch adapter must be closed to allow the diagnostics program to utilize and verify them. After performing the diagnostics, the switch node must then be rebooted to resume normal operations.
In view of the above, commercial advantage would be obtained in the art with a more seamless technique for releasing switch node resources to a diagnostics program from current clients and applications, particularly if without requiring subsequent rebooting of the system.